There are known a wide variety of monetary instruments and banking methods utilizing them. Summarized below are a few examples found in the patent literature:
U.S. Pat. No. 5,044,668 describes a check checker system which employs a check carrying a magnetic strip or bar code containing information permitting point of sale credit approval.
U.S. Pat. No. 5,033,773 describes a document system having improved image security and incorporating a detectable substance which is released from microcapsules in image areas.
U.S. Pat. No. 4,865,351 describes a photo check in which a photograph of a person is disposed upon a check to make quick identification of the person authorized to sign the check.
U.S. Pat. No. 4,681,348 describes a financial document wherein the area in which numerals representing a sum of money to be paid is overprinted in its entirety. U.S. Pat. No. 4,588,211 describes a machine readable document which bears unknown variable data of a specified nature imprinted thereon in unknown, variable locations.
U.S. Pat. No. 3,829,133 describes a form of check incorporating a masked individual code for each check predictable before unmasking only by the authorized drawer of the check, who has advance knowledge of the key by which the individual code for the check is determined.